[article]
| Titre : |
Polyurethanes get a lift : New technology overcames disadvantages associated with non-sagging polyurethane compositions |
| Type de document : |
texte imprimé |
| Auteurs : |
Ralf Guether, Auteur ; Peter. H. Markusch, Auteur ; Robert. L. Cline, Auteur |
| Année de publication : |
2001 |
| Article en page(s) : |
p. 31-36 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Colles:Adhésifs
Composés de moulage en feuille
Polyuréthanes
|
| Index. décimale : |
668.3 Adhésifs et produits semblables |
| Résumé : |
Non-sagging behavior is an essential property for polyurethane and adhesive formulations that are applied onto vertical surfaces. Traditionally, the non-sag property is achieved through additives that control theological properties of a paint or adhesive. For warerborne polymers such as latex paints, rheology modifiers include hydroxyerhyl-cellulose, hydrophobically modified alkali-soluble emulsions and hydrophobically modified ethylene oxide urethanes (associative thickeners). Solvent-based polymers, such as alkyd paints, typically use castor oil derivatives, attapulgite or bentonite clays or fumed silica.
Bayer Corp. has developed a non-sagging polyurethane technology that overcomes disadvantages associated with these filled systems. This technology involves the reaction of a liquid polyisocyanate with polyhydroxy compounds and an aliphatic or aromatic amine. The amines may be added to the reaction in an amount sufficient to produce adequate resistance to flow/sag upon mixing of the reactants. Hence, when a bead of polyurethane is applied to a vertical surface, it does not run, drip or sag. Due to the almost immediate reaction of the amine component with the isocyanate, an initial build-up in molecular weight produces the desired non-sagging behavior. The system remains in this "B-stage" for a controllable amount of time before the hydroxy/isocyanate reaction rakes place and the system cures to a solid polyurethane.
This article describes the basic principles of non-sagging polyurethane compositions as well as a wide variety of applications for this technology. Applications for non-sagging polyurethanes include structural adhesives for SMC, expandable caulkings and sealants, furniture edging, carpet seam sealants, and flexible, sandable patching compounds. |
| Note de contenu : |
- Amine-terminated polyethers
- TDI prepolymer hydrolysis
- Aminocrotonate process
- Mesylate process
- Chloronitrobenzene process
- Structural adhesives for SMC
- Expandable caulkings & Sealants
- Furniture edging
- Seam sealants
- Sandable patching compounds
- Fig. 1 : Polyurea formation
- Fig. 2 : Typical amines
- Fig. 3 : Synthesis of ATPEs |
| En ligne : |
https://drive.google.com/file/d/1a2zAvnMyI9PdJCe052wKyaGBXnam7GeM/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=19733 |
in ADHESIVES AGE > Vol. 44, N° 1 (01/2001) . - p. 31-36
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Polyurethanes get a lift in ADHESIVES AGE, Vol. 44, N° 1 (01/2001)
